Dry cleaning machine



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DRY CLEANING MACHINE Original Filed July 31, 1963 8 Sheets-Sheet 1 I5!204 I 7H I50 l 206 u m' '4 INVENTOR;

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DRY CLEANING MACHINE Original Filed July 31, 1963 8 Sheets-Sheet 4 247243 254 INVENTOR.

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DRY CLEANING MACHINE Original Filed July 31, 1963 8 Sheets-Sheet 6INVENTOR. CLIFFORD F. CzEcH BY Way/WW1, wmam Sept. 6, 1966 c. F. CZECHDRY CLEANING MACHINE 8 Sheets-Sheet 7 Original Filed July 31, 1963 z ubbk P! z INVENTOR. Cum-wan F. Czscu BY M,MM/,

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DRY CLEANING MACHINE Original Filed July 51, 1963 8 Sheets-Sheet 8 TIMERSPIN SAFETY TUMBLE TUMBLE'FAST AIR VALVE T MBLE- SPIN MOTOR 01mm VALVEHEATER BLOWER INVENTOR. Cur-Pom: F. CzecH BY 41 4 MM ommm Anvs.

United States Patent 3,270,530 DRY CLEANING MACHINE Cliiford F. Czech,Ripon, Wis., assignor to McGraw- Edison Company, Ripon, Wis., acorporation of Delaware Original application July 31, 1963, Ser. No.298,899, now Patent No. 3,250,097, dated May 10, 1966. Divided and thisapplication June 30, 1965, Ser. No. 482,000

2 Claims. (Cl. 68-18) This is a division of application Serial No.298,899, filed July 31, 1963, now Patent No. 3,250,097.

The present invention relates to dry cleaning machines and moreparticularly to automatically controlled dry cleaning machines capableof performing a complete cycle of cleaning and drying without attentionfrom the operator after the cycle is started.

In the past, dry cleaning operations have been carried out in commercialestablishments by operators who have been instructed in the operationand dangers of dry cleaning equipment and materials. Dry cleaningoperations have more recently been made available for use by the generalpublic in stores or establishments set up for the purpose. The customerof such a store or public establishment dry cleans his own clothes orgarments in equipment and with materials of the store owner in returnfor a payment for their use. Such a customer has no knowledge of theoperation or dangers incident to the use of the dry cleaning equipmentand materials.

It is therefore an object of the present invention to provide a drycleaning machine which may be operated in an automatic cycle withoutattention of the operator, except for loading, starting, and unloadingthe machine.

Dry cleaning is generally carried out by the use of volatile solvents,especially organic liquids, such as carbon tetrachloride, ethylenedichloride, perchlorethylene, and others. Perchlorethylene is the typeof solvent or cleaning liquid commonly used in customer operated drycleaning equipment. These solvents and cleaning liquids are relativelyexpensive and may, under certain circumstances, become a health hazard.In addition, eflicient cleaning action by such volatile solvents andcleaning liquids depends on proper conditioning of the cleaning liquid.

A further object of the present invention is therefore the provision ofa dry cleaning machine having means for safely handling the cleaningliquids and vapors therefrom to minimize the hazards resulting fromtheir use. It is a related object to provide means for effectively andconditioning the cleaning liquid used in the dry cleaning process.

Another object is the provision of a dry cleaning machine which requiresa minimum of maintenance on the part of the owner of the dry cleaningestablishment and providing a machine of the type which can be installedto give a pleasing appearance to the customer and at the same time haveits various components readily accessible when maintenance is required.

A further object of the present invention is to provide a dry cleaningmachine which is automatic in operation but requires a relatively smallamount of floor space such that it is particularly suited for publicstores or establishments in business and commercial areas where space isoften limited.

Still another object is to provide a dry cleaning machine of unitaryconstruction such that it may be shipped and installed with a minimum oferection and installation cost.

Other objects and advantages of the invention will become apaprent uponreading the following detailed description and upon reference to thedrawings, in which:

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FIGURE 1 is a rear elevation of a dry cleaning machine embodying thepresent invention;

FIG. 2 is a side elevation of the machine of FIG. 1;

FIG. 3 is a front elevation of the machine of FIG. 1;

FIG. 4 is a cross section of a cartridge type liquid filter used inconnection with the dry cleaning machine;

FIG. 5 is a longitudinal section of a portion of the fluid conduit tothe liquid filter showing means for restricting flow;

FIG. 6 is a perspective of the heater used in the dry cleaning machineof FIG. 1;

FIG. 7 is a section of the lint filter taken along the section line 7-7of FIG. 1;

FIG. 8 is a side elevation of an air diverting valve and condenser shownpartially in section;

FIG. 9 is a cross section of the condenser taken along the line 99 ofFIG. 8;

FIG. 10 is a diagrammatic representation of the cleaning liquid andrefrigerating system of the dry cleaning machine;

FIG. 11 is a horizontal section of a safety door latch;

FIG. 12 is a diagrammatic representation of the electrical controlcircuit of the dry cleaning machine; and

FIG. 13 is a graph representing the timed operation of the controlswitches for a cycle of operation.

While a preferred embodiment of the invention will be described herein,it Will be understood that it is not the intention to limit theinvention to that embodiment. On the contrary, it is the intention tocover all alternatives, modifications, and equivalents as may beincluded within the spirit and scope of the invention as defined by theappended claims.

Referring to FIGS. 1, 2, and 3 of the drawings, a dry cleaning machine10 embodying the present invention is constructed to provide a compactdevice capable of unitary installation and utilizing a minimum of floorspace. For this purpose, the machine is supported by a generallyrectangular frame comprising a base 11 and corner uprights 12 securedthereto. In general organization, the components of the machine arearranged on stages or levels which, starting at the bottom, include aliquid reservoir level 14, a liquid pumping and filtering level 15, atub and motor level 16, an air distribution level 17, and arefrigerating level 18. The terms liquid or solvent as used in thisdescription are intended to refer-to volatile cleaning liquid or solventof the types heretofore described as used for dry cleaning.

Forming the liquid reservoir level 14 is a rectilinear tank 20 whichalso serves as the base support 11 for the machine. The bottom and topof the reservoir are rectangular metal plates 20a, 20b of the same sizeand shape as the cross section of the machine. To each corner of thebottom and top plates is fixed an upright corner post 12, as by welding.In the illustrative machine, the corner posts 12 are angle irons forincreased strength and rigidity. Between the top and bottom reservoirplates 20a, 20b reservoir side plates 20c, 20d are sealed to their edgesto complete the reservoir or tank 20.

Supported by the top reservoir plate 2017 are pumping and filteringmeans 'for the cleaning solvent. As shown in the drawings, these meansare mounted and supported by the top plate 20b of the reservoir or tank20. The pumping means comprises a fluid pump 21 having an inlet conduit22 which leads from the pump intake downwardly through the top plate 20bof the tank to a point near the bottom of tank 20. Driving the solventpump 21 is an electric motor 24 such that cleaning liquid from the tank20 is circulated by the pump 21 through an outlet conduit 25 to theinlet of filtering means in the preferred form of a replaceablecartridge type filter 26. The filter is enclosed in a cylindrical shell27 having an inlet connection 28 and an outlet connection 30 in one endwall.

The other end of the shell is closed by a removable cover 31 to permitthe filter material to be removed and replaced when dirty.

One form of filter used in connection with the present machine is showndiagrammatically in FIG. 4 of the drawings. In this construction thereplaceable filter element includes pleated filter material 32 such assuitably fabricated cellulose, paper or like material for extractingparticles of dirt, .sludge, and like impurities from the cleaning liquidor solvent. In the construction illustrated the pleats of the filtermaterial 32 are made from a continuous cylindrical sheet and extendradially from a center cylindrical retainer 34 to the inside wall of theouter shell 27 with the grooves between the pleats extending axially ofthe shell. Solvent to be cleaned is admitted to the outside of thepleats, filters through the filter material, and flows radially inwardlythrough the inner retainer which is perforated for this purpose. Spacedinside of, and generally concentric with, the retainer 34- is a secondcylindricalretainer 35 similarly perforated to permit the passage ofsolvent to the hollow center passage which leads to the outletconnection 30 of the filter. The annular space between the two retainers34, 35 is filled with an adsorbent material 36 such as powdered carbon,for further purifying the solvent which flows through it by removingcolorant-s, odors, fatty acids, and the like. I

It has been found that the flow of cleaning liquids through the filterresults in the formation of small channels or open cracks through thepowdered carbon. These channels or cracks permit the cleaning fluid topass through the layer of carbon without substantial or efficientpurification. A novel means has been provided which reduces the tendencyof the powdered material to form such channels or cracks. In the presentinstance this means comprises a restriction or orifice inserted in theconduit 25 which interconnects the pump 21 and the filter 26. For thispurpose, a relatively thin circular disk 38 having a hole in its centeris fixed crosswise of the conduit 25. By way of illustration therestrictor can be inserted in the conduit by cutting the conduit 25,threading the adjoining ends of the conduit, inserting the disk betweenthe ends and connecting the ends together with a pipe union 39. It hasbeen found that when using three-quarter inch iron pipe which has aninside diameter of approximately five-eighths of an inch, a disk aneighth of an inch thick with a hole three-eighths of an inch in diameteris elfective to increase the efliciency of the filter and prolong itsuseful life. It is believed that the restrictor or orifice may cause theformation of eddies or pulses in the flow of liquid to the filter suchthat the powdered carbon and even the sediment collected on the filtermaterial is jarred and repositioned, thus closing up incipient channelsor cracks which may have been formed.

Also located on the pumping and filtering level of the machine is meansfor filtering or screening large particles such as lint, buttons, andthe like from the cleaning liquid. For this purpose a perforated opentop container 40, made of perforated sheet material or screen, issuspended from the top plate 201) of the reservoir through an openingtherein. As shown in FIG. 2, an outwardly extending horizontal flange isformed around the top edge of the container and rests on the top plate2% about the container opening. Projecting upwardly from the top plate20b, outside of the area supporting the filter container flanges is avertical wall 42 which completely surrounds the flange supporting area.Resting on top of the wall 42, or hinged to it if desired, is a cover 44which can be opened to permit the filter basket 40 to be removed forcleaning. Through the sides of the wall 42, cleaning liquid return -ordrain conduits 45, 46 project such that used cleaning liquid flows intothe filter basket 40 before entering the reservoir. It is one aspect ofthe present filter that the basket 40 extends substantially below thelevel of cleaning liquid in the reservoir 20 to keep the screening andfiltering area submerged. In this manner lint in the return cleaningliquid from clothes which have been cleaned has less tendency to matagainst the perforated basket walls and cause clogging. By the describedarrangement the lint tends to remain suspended in the liquid within thebasket, leaving the basket perforations open.

Supporting the next upper level of components are front-to-back sidechannels 47 welded or otherwise fastened to the corner uprights 12 and afloor plate 48 fixed thereto. At this third level is positioned aclothes tub 49 and perforated inner clothes basket 50 with its powermeans including an electric tumble motor 51 and an electric spin motor52. The clothes tub 49 is, in the exemplary form, a cylindrical tubmounted on a horizontal axis with front and back end walls 54, 55, andhaving depending support brackets or yokes 57 to hold the tub inposition. Within the tub 49 is the cylindrical clothes basket 51supported by an axle shaft 56 extending rearwardly from a back Wall 58and journaled in bearings in the rear wall of the tub 49 for rotation ona horizontal axis coincident with the axis of the tub. Suit able bearingand axle means for the basket are well known in the art and need not bedescribed in detail. The front wall 54 of the tub and the front wall 59of the clothes basket have alined central openings 60, 61 for loadingand unloading the basket 50. For drying clothes in the basket 50 aftercleaning, there is provided an annular passage 62 around the loadingopening formed on its rear side by a forwardly opening C shaped bend 62ain the tub front wall around the opening 60 and formed on its front sideby a rearwardly opening circular channel or collar 62b of C shape fixedto the front wall 62. The collar 62a has an opening in its top portionto receive drying air and to discharge it into the clothes basketthrough apertures 64 in the inner surface of the annular structure. Flowof air through the clothes basket and tub exhausts through a conduitfitting 65 fixed to the tub 49 at an upper side portion approximatelymidway from front to back and overlying an opening formed in the tubside wall.

The clothes tub 49 is also provided with means for intr-oducing anddraining cleaning fluid or solvent. In the machine of the drawings,cleaning fluid is introduced through a pipe or conduit 66 which connectswith an opening in the tub wall adjacent the forward end and above themid line of the tub. Drainage from the tub 49 is formed by afront-to-rear trough formed in the bottom of the tub side wall and adrain opening therein to which is connected the drain conduit 45.Interposed in the drain conduit is an electrically operated solenoidvalve 68 for purposes to be described later.

For carrying out the cleaning, rinsing, and drying steps of the drycleaning process, means are provided for rotating the clothes basket atthe proper speed for each operation of the cleaning cycle. In theillustrative machine these means comprise the tumble motor 51, spinmotor 52, and speed reducing transmission mechanism. Tumble motor 51 isa two-speed motor having a four pole winding 51a which when energizedrotates the motor shaft at approximately 1750 revolutions per minute anda six pole winding which when energized rotates the motor shaft atapproximately 1150 revolutions per minute. The tumble motor shaft isconnected to the clothes basket shaft 56 through a double-speed do-wnpulley and belt transmission including motor pulley '70 which drives alarge intermediate pulley 71 through belt 72. Large pulley 7 1 is fixedon a common shaft 73 to drive a small intermediate pulley 74 which inturn drives a larger pulley 75 on the clothes basket shaft 56 throughbelt 76. The ratio of sizes of the respective pulleys is such that thebasket is turned at about 50 revolutions per minute at the slow motorspeed during the washing, rinsing, and air drying operations.

The spin motor 52 in the exemplary machine is a single speed motor ofapproximately 1750 revolutions per minute and drives the clothes basketthrough a motor shaft produce safety and health hazards.

pulley 78 and a larger pulley 79 fixed to the clothes basket shaft 56. Abelt 80 interconnects the pulleys which have a ratio of sizes to spinthe tub at approximately 500 revolutions per minute and producesuflicient centrifugal force to extract a large portion of the cleaningliquid held by clothes saturated during the washing operation. In orderto bring the clothes basket up to extracting speed rapidly and withoutoverloading the spin motor or, in the alternative, using an expensivehigh powered spin motor, means are provided for energizing the highspeed winding of the tumble motor 51 concurrently with the spin motor52. When this is done the power of both motors contributes to theinitial acceleration of the clothes basket. The tumble motor, because ofits large speed reduction transmission system, assists until the basketspeed approaches seventy-five revolutions per minute. Thereafter, thespin motor which now has attained an appreciable speed continues theacceleration to spinning speed. So that the spin motor will not berequired to pull the tumble motor upon continued acceleration, thetumble pulley 75 on the clothes basket shaft is drivingly connectedthereto by a suitable 1one-way or overrunning clutch 81, theconstruction. of which is well known in the art.

Proceeding now to the air distribution level of the dry cleaningmachine, means are provided for circulating heated air into and out ofthe clothes drum or tub for final drying of the clothes following thecentrifugal extraction. Means are included for heating the drying air,condensing out evaporated cleaning liquid and conditioning the clothesfollowing drying. Starting with the heating means, a rectangular casing83 having an arcuate undersurface to conform to the curvature of theclothes tub 49 is mounted directly on the top of the tub. The

forward end of the casing 83 projects over the front of the tub 49 andhas a vertical leg which extends downwardly to the air passageway 62surrounding the tub loading opening 60. Within the horizontal portion ofthe casing are electrical resistance heating elements 84 of -to thefront of the casing and downwardly to the air passage 62 in the clothestub 49.

In order to control both the temperature of the heating elements and thedrying air, two thermostatic control switches 90, 91 are placed in thetop of the casing 83 at its forward end. Safe operation of the heaterrequires that the surface temperature of the heating elements does notexceed a predetermined maximum temperature. Higher temperatures maycause decomposition of any cleaning liquid retained in the drying airand otherwise To minimize this danger, a safety thermostatic switch 90is set to operate at about 200 degrees Fahrenheit. It has been foundthat by varying the position of the heating elements relative ,to thesafety thermostat, the safety thermostat will indicate excessive surfacetemperature of the elements. For this purpose, the heating elementsupport frame 86 is .adjustably mounted in the casing by means ofthreaded fasteners or screws 92 which adjustably position and hold theheating elements in proper relation to the safety thermostat. It isintended that the proper adjustment be made when the machine isinitially tested at which time accurate measurements can be made ofelement temperature and corresponding operation of the safetythermostat. If the element temperature is too high, when thethermostatic switch is actuated, the elements are moved toward thethermostat. Conversely, if the heating element temperatures are too lowwhen the safety thermostat oping the maximum air temperature in theevent of failure of the air control thermostat 91. In normal operation,the air control thermostat 91 is set to operate at a lower temperaturethan the safety thermostat, for example, at 140 degrees Fahrenheit, suchthat drying air leaving the heater and entering the clothes tub 49 is ator slightly below the setting of the air control thermostat.

Drying air exhausts through exhaust fitting 65 and through conduit 95 tomeans for filtering lint from the air stream. For this purpose, asubstantially self-cleaning filter is provided in the form of arectangular enclosure or box 96 supported by the framework of themachine substantially directly above the tub exhaust outlet 65. Theforward end of the filter box is closed and the rear end which is moreor less flush with the rear of the machine frame has a removable door 97held in place by latches 98 or other suitable means. Within the filterbox is a rectangular frame 100 covered with a relatively light, closelywoven fabric or cloth 101. The filter frame and cloth are supported inthe filter box above an air inlet in the bottom of the filter and belowan outlet 102 in the side of the box adjacent the top. The filter frame100 is dimensioned to extend from side to side and end to end of the box96 so that all air must pass through the filter cloth 101.

One of the features of the present filter is that the cloth 101 is notstretched tightly on the frame but, instead, hangs loosely which,together with the upward flow of air through the filter, providesself-cleaning. Any vibration of the filter cloth as by air floworvibration of the machine frame when the power units are operatingflexes the cloth sufficiently to knock off accumulated lint which thendrops to the bottom of the filter box where it may be periodicallyremoved. In the preferred form the filter frame 100 is slightly longerthan the length of the filter box 96 and extends diagonally from theupper corner of one end to the lower corner of the other end, giving amaximum of filter area for a given size of filter box.

From the filter outlet 102 the drying air passes through a metal fitting104 and a flexible conduit 105 to the intake of a centrifugal fan orblower 106. The blower 106 has a scroll-shaped housing with an upwardlydirected outlet that is connected to an air diverting valve 108. Theblower 106 is supported by one of the rear corner uprights 12 and ahorizontal cross member 109 and is driven by an electric motor 110positioned above the blower.

The air diverter valve 108 provides means for operating the airdistribution either as a closed system or as an open system. In view ofthe relatively high cost of the cleaning liquid normally used in a drycleaning operation, the closed'system permits recovery of substantialamounts of liquid from the drying air. However, in order to remove odorfrom the clothes after drying and to prevent noxious vapors of thecleaning liquid from contaminating the cleaning establishment, the opensystem is used. To accomplish this, the diverter valve 108 of anysuitable construction capable of directing an inlet flow of air toeither of two outlets may be used. In the preferred form, the divertervalve comprises a vertical inlet passage 111, and an interconnectingtransverse outlet passage having one end forming an exhaust outlet 112and the other end forming an air return outlet 114.

At the juncture of the inlet passage 111 and transverse passage aflapper valve gate 115 is pivotally mounted at its upper end so that itsfree end swings across the inlet passage 111 and alternately in front ofthe exhaust outlet and the return outlet. A spring biased electricsolenoid 116 operating through a crank arm 117 fixed to the flapper gate115 normally holds the flapper gate 115 to divert the air flow to theexhaust outlet 112, and when energized pulls the flapper gate 115 acrossinlet passage 111 to divert air to the return outlet 114.

In the air exhaust position of the diverter valve 108 the blower 106draws air from the clothes tub and the same flows through the divertervalve exhaust outlet 112 to an exhaust conduit or stack 119' which takesthe exhaust fumes and air usually to an elevated point outside thecleaning establishment. In the air return position of the diverter valve108, the air from the blower 106 is conducted by air conduit 118 to acondenser means 120 to recover from the air evaporated cleaning liquid.

The condenser means 120 constructed in accordance with one aspect of thepresent invention comprises air cooling means for reducing thetemperature of the cleaning liquid vapor to condense the same and safetymeans to permit continued how of air in the event the cooling meansbecomes coated with ice. It has been found that sufficient water vapormay be present in the drying air to cause substantial icing of thecooling means and after continuous operation of the machine through anumber of cycles to cause serious blocking of the air flow through thecondenser to the heater 83. When this occurs the heater elements mayreach undesirably high temperatures because of insufiicient air flow tocarry away the heat generated at the normal rate.

Referring in more detail to the condenser 120, the air cooling means isformed by a series of tubes or conduits 121 extending across the mainair passage of the condenser. The tubes are joined at their ends by Uconnectors 123 to form a single continuous conduit through which coolingfluid is forced. Parallel to the flow of the air are closely spaced fins122 soldered or otherwise fixed to the coolant tubes. Air is divertedpast and between the fins by top and bottom plates 124, 125, side plates126, and end plates 127. It is the narrow spaces between the fins 122which may become filled with ice to the point of blocking the flow ofair. The safety means to permit air flow even under such a conditioncomprises a bypass channel or passage under the bottom air guide plate125 and the bottom outside wall 129 of the condenser casing 130. Topermit air flow through the by-pass, holes or slits 131 are provided inthe bottom guide plate 125 longitudinally outwardly of the respectiveends of the cooling coils and fins 121, 122. This by-pass, being removedfrom the low temperatures of the cooling coils, remains free of iceblockage. In normal operation only a small proportion of the air goesthrough the by-pass because of the lower resistance and larger area ofthe main passage, but has sufiicient area to carry substantial airvolume if necessary.

Condensed cleaning solvent and water which is extracted from the air bythe coo-ling means drips down to the bottom guide plate 125 and throughsuitable drain holes into the bypass area. A drain connection 132 in thebottom casing wall 129 carries the condensate through a conduit 134 tothe left leg of a U tube separator 135. The U tube separator has a firstoutlet 136 in the left leg above the inlet conduit connection forreturning condensed cleaning liquid to the reservoir 20 through tube 46.Because of its higher specific weight water mixed with condensedcleaning liquid settles to the bottom of the U tube and is forcedupwardly into the right leg of the separator. An outlet 139 in the rightleg positioned above the inlet conduit connection, but below the outletconnection 136, drains water from the separator through tube 140 whichmay lead to any suitable Waste disposal means.

As previously described, the air circuit for the closed system iscompleted by air flowing into the condenser 120 through inlet 142 in oneend wall of the condenser casing 130, through outlet 143 and throughconduit 144 to the heater inlet 88. Completing the open system is anormally open inlet air valve 146 mounted on the rear top wall portionof the heater casing 83, to allow atmospheric air to be drawn into theheater casing and thence to the tub 49. .Upon energizing an electricalsolenoid 147 sup-ported above the valve 146 a valve plate seats to closethe valve. As will be further explained, fresh atmospheric air is usedat the end of the cleaning cycle to remove odor and freshen the clothes.

At the top of the corner uprights 12 of'the machine frame cross pieces150 interconnect the uprights 12 to complete the frame, giving itrigidity and also form the support for the refrigerating means. Therefrigerating mechanism may be of any suitable type, comprising a sealedcompressor unit 151 driven by an electric motor 152, a cooler 153 forthe compressed refrigerant, acooling fan and motor unit 154, and anexpansion valve or cap tube 155. Refrigerating apparatus of theforegoing type is well known and commercially available and hence neednot be described in detail. Of interest in connection with practicingthe present invention is the flow circuit of the refrigerant from theexpansion valve 155 through conduit 157 to the condenser coils 121 andthen through conduit 158 to a cleaning liquid heat exchanger or cooler16% mounted on the top of the frame adjacent the refrigeratingmechanism.

As will be seen, the dry cleaning machine as previously described formsa unitary structure supported by the uprights 12 and within the confinesof the base 11. The front of the machine may if desired have .a completepaneling covering the entire front of the machine or, if preferred, mayhave only a partial panel surrounding the loading opening with auxiliaryor wall paneling covering the remainder of the front. In either case itis intended that the machine will be installed as a built-in unit with awall partition extending from each edge of the front face of themachine. By this construction, the customer or operator has access onlyto the loading door and opening. The space behind the wall partition mayalso be separately ventilated for additional safeguard to the area ofthe establishment to which the customers or operators are admitted.

Referring now to FIG. 10 there is shown diagrammatically the piping andequipment which circulate and condition the cleaning liquid or solvent.The circuit illustrated comprises means for supplying filtered cleaningliquid to the clothes and return, means for maintaining the cleaningliquid at efiicient working temperature, and means for recovering theevaporated cleaning liquid from the drying air. The circulating pump 21as previously described pumps cleaning liquid from the storage tank 20through suction line 22 and forces the liquid through conduit 25 to thefilter 26 and from the filter outlet 30 through conduit 161 to apressure relief valve 162 which is normally open to tub supply conduit164 and discharges to cooler conduit 165 upon excess pressure build-upin feed line 161. Interposed between tub supply conduit 164 and the tubsolvent inlet 66 is a normally closed solvent control valve 166 which ispro vided with an electrical solenoid control opening the valve 166 whenenergized to introduce cleaning liquid to the tub during the washingperiod of the cycle.

One of the features of the present invention is the provision of meansfor reducing the dry cleaning cycle by insuring rapid saturation of thegarments or clothes and a rinse or second wash. For this purpose, anormally closed valve 68 moved to open position upon energization ofelectrical solenoid control 168 is placed in the tub drain conduit 45.During the initial portion of the washing period, the drain valve 68 isclosed permitting the clothes tub to partially fill with cleaning liquidand the clothes to be saturated quickly. Approximately half way throughthe washing period after the clothes have tumbled in the liquid,solenoid 168 is energized allowing the dirty cleaning liquid to drainfrom the tub 49. Solenoid 168 is then deenergized allowing the drainvalve 68 to close and the tub 49 is again partially filled with cleanliquid for the balance of the wash. At the end of the washing period,solenoid 168 is once again energized, holding valve 68 open during thehigh speed spin period to permit the extracted cleaning liquid to drainto the storage tank 20. In the air drying period solenoid 168 isdeenergized closing the drain valve 68 so that there is no tendency forair to be circulated through the drain line 45 with possible evaporationof solvent in the storage tank 20.

During the time that cleaning liquid is not used to fill the clothes tub49, the liquid is continuously filtered or cooled, if needed, exceptduring a portion of the air drying period. For this purpose coolingmeans in the form of a heat exchanger or cooler tank 160 receivescleaning liquid upon closing of the tub inlet control valve 166, theclosing of which causes a pressure rise in feed conduit 161 openingrelief valve 162 to cooler conduit 165. The cooler 160 is a cylindricaltank having an inlet connection to conduit 165 and an outlet to returnline 169, the latter leading to the storage tank 20. Within the cooler160 is .a refrigerant coil 170 formed of suitable tubing. One end ofcoil 170 is connected to refrigerant line 158 leading from the condenserand the other end is connected to the refrigerant compressor 151 throughline 171. The cooler coil 170 is adapted to receive and utilizerefrigerant in series with the condenser coils 121. Such an arrangementin which one heat exchanger receives refrigerant from another isreferred to in the refrigerating art as a tail off system.

Means are provided in the form of a thermostatic element 173 placed inthe liquid storage tank 20 for measuring and controlling throughthermostatic switch 174 the temperature of the cleaning liquid. It isdesirable to keep the temperature in the neighborhood of 75 to 85degrees Fahrenheit. As will be explained presently, additional controlmeans cooperating with the thermostatic switch 174 provide additionalcooling .of the liquid, if necessary, tokeep its temperature within thepreferred range.

In connection with the means for recovering cleaning liquid from thedrying air, which includes the previously described condenser 120 andwater-separator 135, control means, in the form of thermostatic element175 and electric switch 176 controlled thereby, is provided.Thermostatic element 175 is placed in the air stream on the outlet endof the condenser 120 for the purpose of measuring the cooled airtemperature. If the temperature of the air leaving the condenser risesabove a predetermined temperature, which is about 100 to 110 degreesFahrenheit for perchlorethylene, the liquid is not being properlyextracted from the drying air by the condenser. The thermostatic elementat such high temperatures closes the normally open switch 176 to stopmachine operation.

The automatic, sequential operation of the exemplary embodiment will nowbe explained with reference to FIG. 12 in which a control circuit forautomatically sequencing the power units and operating valve meansthrough a complete cycle of washing and drying clothes is showndiagrammatically. In addition, the control circuit incorporates safetydevice to protect both the operator and the physical components of themachine in the event of power failure or malfunction.

- Power for operating the various operating and control devices isprovided by an electrical source, not shown, having a conventionalthree-wire conduct-or comprising two high voltage conductor-s 201, 202,and a neutral conductor 203. A two-pole manually operated master switch204 physically positioned on the upper level of the machine frame isconnected in series with the high voltage conductors 201, 202, and whenclosed, completes a circuit from the power source to the machine. Forconvenience the two high voltage conductors are represented through thediagram of FIG. 12 as L and L and the neutral conductor as N. Ingeneral, the control and small power devices are connected to andenergized by conductors L and N, while the heavy duty power devices,such as the refrigerating unit and the heater, are energized by L and LProviding proper sequential control of the machine operations is aseries of cam operated switches driven in timed sequence by a timermotor 205 and illustrated diagrammatically as S1 through S10,respectively. The

timer motor, cam operated switches and associated relays are mounted ina control box 206 on the upper rear of the machine frame. Timer motorsand cam switches are known in the automatic laundry field and do notrequire detailed explanation. Suffice it to say that the timer motor 205drives a cam shaft which rotates a series of cams coa-cting with thevarious switches S1 through S10 to open and close the same atpredetermined degrees of cam shaft rotation. The preferred sequence ofopening and closing of the switches is represented on FIG. 13 in whichthe switch contacts engaged by the cam switches are represented byreference letters corresponding to the letters appearing on the circuitdiagram of FIG. 12. The horizontal axis of the chart of FIG. 13 isdivided into equal increments of rotation of the cam shaft which arealso equal increments of time, except for one increment indicated asnumber eighteen. An entire cycle of opera tion is representedbytwenty-five increments and, with the exceptions noted, comprises a cycleof slightly over 15 minutes. The increments of the cycle during which aswitch contact is closed are shaded on the chart. The switch contact isopen during the increments which are unsh-aded.

The illustrative control and power circuit of FIG. 12 is initiallyenergized, assuming the master switch 204 is closed, by the closing ofnormally open contacts 207a, 2071: of the main solenoid relay 208. Themain relay solenoid 208 is energized through a plurality of safetydevices which will 'be described hereinafter. Main relay contact 207b isconnected to power line L and contact 207a is connected to terminal Y ofstandby cam switch S1, to one terminal 209 of the timer motor cam switchS10, to one switch contact 21% of a power relay 212 and to one side of amanual start switch 213.

At the beginning of a cycle the timer mechanism is conditioned forenergizing the timer motor 205 through cam switch S10, the slow speedwinding 214 of clothes tumble motor 51 and the air intake and airdiverting solenoids 147, 116. For this purpose, standby switch contactU, air valve switch contact AV, and low speed tumble motor switchcontact M are engaged by their respective cam switches S1, S6 and S8.The cycle can now be initiated by manually closing start switch 213which energizes the power relay closing normally open switch contacts210a, 21% and 215a, 2151). Timer switch contact U, being energized frompower line L through cam switch S1 in turn energizes power relaycontacts 215a, 215!) which complete an electrical circuit to the timermotor through connectors 217, 217a and timer advance switch contact 218astarting the timer motor 205. The second set of power relay contacts210a, 210b completes a circuit from the main power relay switch 207 totimer switch contact X and the common timer cam switch conductor 219through conductors 220, 221, 222.

Although a manual start switch 213 is shown in the diagram of FIG. 12,it will be appreciated that a coin operated switch mechanism may besubstituted if the dry cleaner is to be used in a public coin operatedstore. Various forms of such coin operated switch mechanisms are knownin the art and include selector mechanism to determine the number ofcoins to be inserted, reset mechanism and coin rejectors. Electricalpower for ope-rating such coin devices can, for example, be obtainedfrom the power relay normally closed switch contact 2150 which isenergized through timer switch contact U, before the power relay isactuated. For resetting either the manual start switch 213 or the coinmechanism after operation is commenced, a wipe-out relay 224 isenergized by the closing of an appropriate timer switch contact afterthe cycle has commenced, such, for example, as contact WD which isenergized during the twentyfirst timed increment.

During the first timed increment, no cleaning operation is performed.The clothes are merely tumbled in the tub. However, means are providedduring this incrementfor insuring that the cleaning liquid is in propercondition for the subsequent cleaning. For this purpose means areprovided for energizing the liquid circulating pump motor 24concurrently with the timer motor 205. In more detail, a normally openpump relay switch having one terminal 22511 connected to power line Land the other terminal 225a to the solvent pump motor 24 is actuated bypump relay solenoid 226, one side of which is connected to the timermotor conductor 217 and the other to neutral N. Thus, whenever the timermotor is energized, except by use of the timer advance switch contact218b, the solvent circulating pump is also energized through relayswitch 225. This circulation of solvent prior to cleaning has been founddesirable for preventing the initial charge of solvent into the tub fromcarrying with it impurities such as may be present in a stagnantquantity of solvent. The precirculation of solvent also serves tocondition the filter which may, upon standing without circulation,permit impurities to pass through.

Also, during the first increment, the refrigerating unit compressormotor 152 will be energized by means of thermostatic switch 174 andrefrigeration relay switch 228 if the cleaning liquid temperature in thestorage tank 20 exceeds the predetermined maximum as indicated bythermostat 173.

The timer motor, upon rotation of the cam shaft to the second timedincrement, causes the timer motor and solvent valve cam switches S10 andS to close energizing contacts TM and P. Closing of contact TM completesa circuit for the timer motor through connector 217a, switch contact TM,terminal 20?, and connectors 239, 231, to the main relay switch 2il7a.This circuit is in parallel to the timer motor energizing circuitthrough standby cam switch U and power relay contacts 215a, 215b, andinsures continuous operation of the timer motor when standby cam switchU subsequently opens. The closing of the solvent valve cam switch Penergizes solenoid 233 which controls the tub inlet valve 166 openingthe latter to introduce cleaning liquid into the clothes tub. Aspreviously explained, the cleaning liquid which during the firstincrement of time flowed through the cooler tank 160 now flowscompletely into the tub due to the closing of pressure relief valve 162.The low speed tumble motor cam switch M is still closed causing theclothes to be tumbled in the cleaning liquid to provide the necessarycleaning action.

On the third increment of the timer, standby cam switch S1 opens contactU and closes cam contact X. The closing of operating cam switch Xenergizes the common timer conductor 219 from the main relay switchcontact 207a through an alternate circuit including connector 231,terminal Y, cam switch S1, and connector 222. The purpose for thisalternate connection is to condition the circuit for continuedenergization of the timer switch terminals after the power relay 212 isdeenergized at a subsequent increment of the timer control. In theparticular circuit shown, the opening of standby cam switch contact Udoes not immediately deenergize the power relay 212, since the manualswitch 213 is still closed.

During timed increments two, three, and four, the clothes container isfilling with cleaning liquid and the tub is rotating at slow or tumblespeed. However, at timed increment four, the solenoid operated drainvalve 168 is energized through the closing of drain cam switch S4 andcontact PV, thereby opening the valve 68 and allowing the cleaningliquid to drain from the tub. The drain valve solenoid 168 isdeenergized at timed increment five, permitting the drain valve 68 toagain close and the clothes tub 49 to refill for a second cleaning ordeep rinse. This continues for two timed increments, after which thedrain valve solenoid 168 is again energized by the closing of drain camswitch S4 and contact PV and remains energized during timed incrementseight 12 through fifteen, that is, up to and through a final rinse andthrough a high speed rotation of the clothes basket 50 to extractsolvent from the clothes by centrifugal action.

The final rinse of the clothes is accomplished during timed incrementseight and nine since the solvent inlet valve 166 remains open uponcontinued energizing of the inlet valve solenoid 233 for these twoincrements.

During timed increment ten, solvent valve cam switch S5 opens contact Pdeenergizing the inlet solenoid 233 and closing the inlet valve 166which remains closed for the balance of the cycle. At the same time, themain motor cam switch S8 is moved from the low speed tumble contact M toa higher speed contact A to energize the four pole Winding 234 andsimultaneously spin motor cam switch S7 closes contact T to energize thespin motor winding 235. As previously described, the speed of theclothes basket rotation is initially accelerated by the operation ofboth the tumble and spin motors 51, 52, and finally brought up to fullspeed by the spin motor 52. The one-way clutch or overrunning clutch 81interconnecting the main motor 51 and the basket drive shaft 56 permitsthe spin motor to drive the basket 50 at a greater speed than the mainmotor without disconnecting the main motor drive. During spin at highspeed, the main motor 51 is energized, but since it is doing no work,very little electrical power is used.

The spinning of the clothes basket 50 at high speed is continued forseven timed increments through the sixteenth increment as shown on FIG.13 and extracts most of the cleaning liquid from the clothes, leavingthem in condition for final drying. Prior to the actuation of motor camswitches S7 and S8 to open contacts A and S at the end of the spinperiod, heater elements 84 are energized by the closing of cam switch S3and its associated contact H at the beginning of timed incrementsixteen. Because of the high voltage and relatively heavy electriccurrent required for the heater, a heater relay 236 with switch contacts237a, 2371) is used. As shown in the diagram of FIG. 12, the heaterrelay coil 236 is connected to power line L through cam switch H and tothe neutral power line N. Upon actuation the relay coil closes relayswitch contacts 237a, 2371) completing a circuit from L to one side ofthe heater elements 84, the other side being connected to power line LAt the end of timed increment sixteen the motor cam switches S7 and S8open contacts A and T, deenergizing the motors 51, 52 and allowing theclothes basket to coast to a stop during one timed increment, which isshown as increment seventeen.

Rotation of the clothes basket 50 is again resumed at the beginning ofincrement eighteen when the main motor cam switch S8 is cammed intoengagement with contact M, starting the main motor 51 at tumble speedfor the remainder of the cycle. The clothes are now being tumbled inheated air to evaporate from them the residue of solvent left aftercentrifugal extraction. The drying is continued until the desired degreeof dryness is indicated by a rise in exhaust air temperature as measuredby a normally open thermostatic switch 91 located in the exhaust airduct 95 leading from the clothes tub to the lint filter 96. Suchvariation in exhaust air temperature, as a measure of dryness, is knownin the art and need not be described in detail. In general, the exhaustair temperature rises gradually to a more or less steady temperatureuntil the clothes are dry or nearly dry, at which time the temperaturerises rapidly. The exhaust duct thermostat 91 is therefore set to closeat a predetermined high temperature in the range of rapidly increasingtemperature. In the preferred embodiment of the invention thistemperature is approximately degrees Fahrenheit.

In order to provide adequate time for drying and to insure propermeasurement of dryness, means are provided for interrupting the timermotor 205 to stop the rotation of the timer cams, and for restarting thetimer motor 205 upon indication that the clothes have been dried. In thepreferred embodiment this is accomplished by inserting a parallel timermotor energizing circuit in series with cam switch S9 and its associatedcontact ST. Connected to switch contact ST is one side of the normallyopen sensing thermostatic switch 91, the other being connected toconductor 217 which leads to the timer motor 205 through conductor 217aand adv-ance switch contact 218a. The Sensing thermostatic switch 91 isconditioned to energize the timer motor 205 by the closing of cam switchcontact ST at the beginning of the fourteenth timed increment. Thecircuit to the timer motor is not completed, however, until thethermostatic switch 91 closes upon a rise in the temperature of the airexhausted from the clothes tub. At the end of the seventeenth timedincrement, the timer motor cam switch S10 opens contact TM and the timermotor stops. The timer cam controls then remain inactive for anindeterminate length of time until thermostatic switch 91 closesindicating that the clothes have been dried to a predetermined degree ofdryness. Upon closing, thermostatic switch 91 energizes the timer motorthrough the eighteenth increment, after which the timer motor cam switchS10 recloses contact TM to establish the normal energizing circuit forthe timer motor. Since the heater cam switch H remains closed during theeighteenth increment of cam rotation, the thermostaticswitch 91 willremain closed until after the timer motor 205 has reestablished itsnormal circuit through cam switch contact TM.

Means are provided during the main drying period for insuring that thecondenser 120 is operated elficiently to take the evaporated cleaningliquid from the drying air. Following the closing of the cleaning liquidinlet valve 164 upon the opening of cam switch contact P at the end ofthe washing period, the pump 21 has been circulating liquid throughpressure relief valve 162 to the liquid cooling tank 160. In order touse the full capacity of the refrigerating unit for the condenser, theflow of cleaning fluid to the liquid cooling tank 160 is stopped duringthe eighteenth increment of cam rotation. This is accomplished by a setof normally closed switch contacts 239a, 2391) actuated by heater relay236, and by the deenergizing of conductor 217. When the heater relay 236closes contacts 237a, 237b to turn on the heating elements 84, switchcont-acts 239a, 239k are opened to break the circuit to the cleaningliquid thermostatic switch 174 and thus prevent operation of the pumpauxiliary relay 240. Upon the opening-of cam switch TM to stop the timermotor 205 during drying, conductor 217 is deenergized causing the pumpmain relay 226 to drop out. Thus, the liquid circulating pump 24 cannotnow be started until either the heater relay 236 is deenergized or thetimer motor 205 is energized. Either of these events in- 'dicates theend of the drying period during which the condenser and refrigeratingunits are under maximum load.

Concurrently with the closing of the heater energizing circuit the aircirculating means is energized 'by the actuation of cam switch S2 toclose contact B which connects one terminal of the blower motor 110 topower line L The other terminal of the :blower motor 110, as with theother low voltage power and relay coil units, is connected to theneutral power line N. The air diverting valve solenoid 116 has beenenergized during the entire period of operation up through the dryingperiod for maintaining the air circulation in a closed system aspreviously described, and remains energized through the twentieth timedincrement.

After the heater timer cam switch H opens at the end of the eighteenthincrement, the timer motor 205, tumble motor 51; and blower'motor 110continue to be energized to tumble the clothes while unheated air isblown through the system. During thisperiod, the drying controlthermostatic switch 91 is disconnected from the circuit by the openingof cam switch ST, and at the beginning of he twenty-first timedincrement the air diverter valve solenoid 116 and the air intake valvesolenoid 147 are deenergized by the opening of cam switch contact AV. Bythis actuation of the cam switches, means are provided for conditioningand deodorizing the dried clothes. The air diverter valve 108 is nowspring biased to divert exhaust air from the blower 106 to the exhauststack or conduit 119 and the air intake valve 146 is opened to permitfresh atmospheric air to enter the air circulating system. Thisdeodorizing and conditioning process continues for four timed incrementsuntil the blower motor cam switch contact B is opened at the end of thetwentyfourth increment.

During the last or twenty-fifth increment of time, the timer motor andthe tumble motor slow speed windings are energized, continuing to tumblethe clothes until the cycle ends When the timer cam means completes thetwenty-fifth increment and switch TM opens. The timer cam switch S1 isactuated at the beginning of the twentyfifth increment to close contactU permitting the loading door 242 to be opened and the control circuitplaced in condition to start another cycle.

When the air diverter and air intake solenoids 116, 147 are deenergizedat the beginning of the twenty-first increment to introduce fresh air,the main power relay 243 of the refrigerating unit is deenergized,opening the associated relay contacts to stop the refrigerating unit.This provides means for reducing the amount of electrical power requiredand permitting defrosting of the condenser caused by moisture picked upfrom the clothes freezing .on the fins. Provision is made, however, bymeans of the cleaning liquid thermostatic switch 174 for overriding thetimer control and continuing to operate the refrigerating units throughrelay switch 228 if the temperature of the cleaning liquid is too high,as previously explained in connection with the beginning of the cycle.

Because of the health hazards involved in the use of volatile cleaningliquids andsolvents, means are provided for adequate ventilation of thedry cleaning machine. To insure that no vapors from the cleaning liquidenter the operators area, means are provided for sweeping the inside ofthe tub with fresh air and exhausting the same to the exhaust stackwhenever the loading door of the machine is open, and to insure that theloading door is closed and locked whenever the machine is operating orhas malfunctione'd.

To accomplish this, a door unlocking means is provided which is operableonly if the cycle has been completed. Referring to FIG. 11 of thedrawings, a door latching and unlocking mechanism constructed inaccordance with one feature of the invention is illustrated. In thisillustrative embodiment, the door 242 is shown in closed position. Atthe free edge portion of the door 242, a handle 243 is securely fixedand projecting inwardly from the handle is a latch member 244 whichprojects through a slot 246 formed in the machine cabinet panel 247. Thelatch member is spring biased either by a suitable coil spring or by itsown resiliency to press against the edge of the slot away from theopening. In order to guide the latch 244 into the slot 246 and to holdthe door closed, the projecting end of the latch has a sloping end face248 and a notch or shoulder 249 positioned inwardly from the end face.The sloping end face which faces diagonally rearwardly away from theloading opening strikes the outer edge of the slot forcing or cammingthe latch toward the loading opening until the latch is in line with thelocking slot 246. Continued closing movement of the door pushes thelatch into the slot allowing the latch to be biased away from theloading opening when the shoulder 249 has entered the slot. The shoulder249, which faces outwardly toward the frame of the machine, then movesbehind the portion of the door panel adjacent the slot and holds thedoor in closed position. Consequently, once the loading door 242 isclosed it cannot be opened by pulling on the 'handle.

To unlock the door, electrically operated means are provided for movingthe latch to unlocked position. In the mechanism of FIG. 11, this meanscomprises an electrical solenoid 250 and an unlocking pin or striker 251axially movable upon energizati-on of the solenoid 250. The unlockingpin 251 and solenoid 250 are mounted on the rear side of the frontcabinet panel 247 by a suitable bracket 253 with the projecting end ofthe pin in alinement with the end of the latch 244 projecting throughthe locking slot 246 on the side away from the loading opening. Theunlocking pin 251 is normally held away from the latch member 244, butupon energization of the solenoid the pin 251 is forced into engagementwith the latch and pushes it toward the door opening until the lockingshoulder 249 is within the slot and free of engagement with the edge ofthe slot. The door 242 may now be pulled open. Normally, there arerubber or plastic seals around the edge of the door to insure a snug fitagainst the cabinet panel. These seals have sufficient resiliency tomove the door open as soon as the latch 244 is free. If desired, springson the door hinges or a spring biased plunger may be used for the samepurpose.

In order to insure that the door unlocking means is operative only whenthe cleaning cycle is complete or has not proceeded to a point ofpossible hazard, the door unlock solenoid 250 is energized through aseries circuit including a normally closed relay contact 2150 on thepower relay switch 215b and cam switch contact U. The latter switchcontact is energized through cam switch S1 only during the first twotimed increments and the last timed increment of the cycle. Power relaycontact 2150 is closed only at the beginning of the cycle before themanual start switch 213 is closed and during the final portion of thecycle after the manual switch is opened by solenoid 224. The latteroccurs in the illustrative circuit upon closing of cam switch contactWD. Consequently, switch contacts U and 2150 are energized concurrentlybefore the machine is started and during the last timed increment, andas will be seen malfunction of the machine will prevent the timermechanism from completing the cycle to allow cam switch U to beenergized.

So that the loading door 242 will not swing open without notice to theoperator, a manual push button switch 254 is inserted in the solenoidenergizing circuit. Thus, at the end of the cycle the operator bypushing switch 254 can unlock the door.-

Also associated with the door and with the door ununlocking mechanismare safety means which deenergize the control mechanism to stop themachine if the door is open or unlocked. For this purpose, a single poledoublethrow switch 256 is mounted on the front panel 247 behind aportion of the loading door 242. The door switch has a projectingoperator which is axially moved by opening and closing of the door. Whenthe door is closed, a normally open switch contact 256a is closed and isconnected to power line L through a safety control switch 257. In serieswith the door switch contact 256 is an unlock switch 258, which in turnis connected to the main relay coil 208. Unlock switch 258 as shown inFIG. 11 is mounted in the path of movement of the unlock solenoidarmature 259 such that the switch actuator 260 is engaged and depressedwhen the solenoid 250 is deenergize d. Operation of the unlock solenoid250 to unlock the door latch 244 opens the switch 259. Opening of eitherthe door switch 256a or the unlock switch 258 breaks the electricalcircuit to main relay 208 causing relay contacts 207a, 2071) to open anddeenergize the entire control circuit, immediately stopping the machineif for any reason it should be inoperative.

In addition to the means for preventing opening of the loading doorexcept under safe conditions and for preventing operation of the machineif in some unforeseen manner the door is either unlocked or openedduring a cycle, means are also provided by use of the door switch 16'256 to provide proper ventilation of the machine when the loading dooris opened. To accomplish this, the door switch 256 has a normally closedcontact 256b electric-ally connected to the blower motor 110 such thatupon opening of the door 242, the blower motor will be energizedindependently of the timer cam switch mechanism to draw air into themachine tub 49 through the open door and exhaust the same to the exhauststack 119. The ex haust diverter valve 108 will be spring biased to theoutside exhaust whenever the door 242 is open since door switch contact256a must be open and hence break the circuit to the main relay 208.

Safety control means for indicating malfunction of the dry cleaningmachine during an operating cycle are also provided, such that when amalfunction is detected the machine is stopped and cannot complete itscycle until the cause is found and corrected. To accomplish this asolenoid operated manual reset switch 257 is placed in the series withthe door and unlock safety switches in the energizing circuit for themain relay 208. Opening of the manual reset switch deenergizes the mainrelay 208, stopping the timer and breaking the power circuit to all ofthe cam switches. The construction of solenoid operated manual resetswitches is commonly known, being in the nature of manually resetcircuit breakers or solenoid operated toggle switches.

In accordance with one feature of the present invention, a plurality ofindicating means having normally open switch contacts adapted to closeupon a predetermined indication are placed in parallel electricalcircuits such that any one of them can open the solenoid switch 257. Oneof these indicating means is the heater safety thermostat mounted at theoutlet of the heater 83 and adjacent the heater element 84. One side ofthe normally open switch of the thermostat 90 is connected to the doorswitch contact 256a and is energized when the door is closed. The otherterminal of the safety thermostatic switch 90 is connected to a switchsolenoid coil. Upon a rise in temperature of the heater and heaterelements above a predetermined temperature, thermostatic switch 90 willclose and energize switch coil 262 to open switch 257 stopping-themachine and shutting off the heaters, since heater relay 236 will bedeenergize-d along with the other control circuits.

The remaining safety indicators are effective only at selected portionsof the cycle. With reference to FIG. 1, means is shown for indicating afailure of the machine to tumble the clothes during the air dryingportion of the cycle. For this purpose, a normally closed, centrifugallyoperated switch 261 is rotatably driven by a pulley or wheel 263 whichbears against the clothes basket drive belt 76. Any suitablecentrifugally operated switch such as is commercially available may beused for this purpose. In the present instance the switch 261 is mountedon a pivotally supported arm 264 and the drive wheel 263 is pressedagainst the drive belt 76 by a tension spring 265. Upon rotation of thepulley or wheel 263 the centrifugal switch 261 opens, and if in case ofmotor failure or breakage of a drive belt the pulley or wheel 263 doesnot rotate, the switch 261 remains closed. In the electrical diagram ofFIG. 12, centrifugal switch 261 is interposed in series in an electricalcircuit from timer cam switch contact WD and switch operating coil 262.-With reference to the time chart of FIG. 13, timer switch contact WD isenergized for the twenty-first time more ment which occurs after theairdrying has been completed. If during this interval the final drivebelt 76 to the clothes basket 50 is not moving, centrifugal switch 261will be closed and cause switch operating coil 262 to open the manualreset switch'257 and thus stop the machine.

The centrifugal switch 261 insures that the clothes have been tumbledduring drying and are not still partially wet, as would be the case ifthey had remained in a tight bundle at the bottom of the'clothes basket.

During the same time interval, condenser thermostatic switch .176, whichis in a parallel circuit with centrifugal switch 261, is also energized.The condenser thermostatic switch 176 is normally open but, upon a risein the temperature in the condenser, will close to energize the switchoperating coil 262. If, during the air drying period the condenser hasfailed to maintain a sufficiently low air temperature, the cleaningliquid vapors will not have been properly removed. Any such improperoperation, regardless of cause, will be indicated by thermostatic switch176.

Means are further provided for indicating failure of the machine toproperly extract cleaning liquid from the clothes during the centrifugalextraction period. For this purpose, a second normally closedcentrifugal switch 267 is mounted for driving rotation by the spin motorbelt 80. The structure and mounting of switch 267 need not be describedsince it is the same as that of switch 261. The spin indicator switch267 has one terminal electrically connected to cam switch contact CS andis energized during the seventeenth time increment, which occursapproximately in the middle of the centrifugal extraction period, asshown in FIG. 13. As a result, failure of the spin motor 52 for anyreason to drive the belt 80 will be indicated by failure of centrifugalswitch 267 to be open when timer cam contact CS is energized. If thecentrifugal switch 267 is closed during that timed increment, themachine will be stopped immediately by the energizing of switch coil 262and opening of switch 257.

In normal use and installation, manual reset switch 257 will be locatedon the rear of the machine or at some other place where theinexperienced operator cannot reset it. Upon determination of themalfunction which has caused switch 257 to open and correction of thedifficulty, switch 257 can be reset. It may be neces sary in suchcircumstances to also reset the timer mecha nism to its beginningposition when the machine has been stopped midway of the cycle. A singlepole, double-throw timer advance switch 218 is provided for thispurpose. One terminal 218a of switch 218 is connected to the normaltimer motor energizing circuit through conductor 217a, and the secondterminal 218b is connected to power line L such that it is alwaysenergized when the master switch 204 is closed. By closing timer advancecontact 218b, the timer motor can be energized irrespective of thecondition of the control circuits and the timer mechanism advanced asdesired.

From the foregoing description, it will be apparent that the applicanthas provided a laundry machine adapted particularly for use with organicvolatile solvents which is capable of unitary construction and which canbe operated by an unskilled operator. The times indicated for individualoperations of the machine may be varied to suit individual preferences,and one or more steps, such as rinsing, may be omitted. Similarly, thepresent machine has been described with numerous safety features some ofwhich under various circumstances may be found to be unnecessary,depending upon the operator using the machine.

I claim as my invention:

1. In a clothes washing machine for use with volatile cleaning solvents,the combination comprising a clothes treating tub, a solvent reservoirfor receiving solvent drained from said tub, means for circulatingsolvent from said reservoir, conduit means for conducting solvent fromsaid circulating means to said tub for washing clothes in said tub, aircirculating means including a solvent condenser and a heater forsupplying dried heated air to said tub for drying the clothes, said aircirculating means also including a blower for withdrawing air from saidtub and a diverter valve for selectively directing air from said blowerto exhaust and to said condenser, said condenser including a main airpassage therethrough having a plurality of cooling fins therein and aby-pass channel of small cross section around said cooling fins for freepassage of air upon blockage of the main air passage by the formation ofice on said cooling fins, and means for draining condensed solvent fromsaid condenser to said reservoir.

2. In a clothes washing machine for use with volatile cleaning solvents,the combination comprising a clothes treating tub, a solvent reservoirfor receiving solvent drained from said tub, means for circulatingsolvent from said reservoir, conduit means for conducting solvent fromsaid circulating means to said tub for washing clothes therein, aircirculating means including a solvent condenser and a heater forrecirculating air through said tub and drying and heating suchrecirculated air for drying the clothes, said condenser having a seriesof longitudinally extending cooling fins transversely spaced from eachother and longitudinally extending walls spaced adjacent said finsdefining a main air passage, an outside Wall spaced outwardly from oneof said main passage walls defining a -by-pass channel of small crosssection, said one of said main passage walls defining openings fordiverting a small portion of air around said cooling fins upon normaloperation and for diverting a substantial flow of air upon blockage ofthe main air passage by the formation of ice on said cooling fins.

References Cited by the Examiner UNITED STATES PATENTS 3,002,287 10/1961Smith 6812 X 3,206,950 9/1965 Xeros 68-12 FOREIGN PATENTS 562,075 8/1923France.

WILLIAM I. PRICE, Primary Examiner.

1. IN A CLOTHES WASHING MACHINE FOR USE WITH VOLATILE CLEANING SOLVENTS,THE COMBINATION COMPRISING A CLOTHES TREATING TUB, A SOLVENT RESERVOIRFOR RECEIVING SOLVENT DRAINED FROM SAID TUB, MEANS FOR CIRCULATINGSOLVENT FROM SAID RESERVOIR, CONDUIT MEANS FOR CONDUCTING SOLVENT FROMSAID CIRCULATING MEANS TO SAID TUB FOR WASHING CLOTHES IN SAID TUB, AIRCIRCULATING MEANS INCLUDING A SOLVENT CONDENSER AND A HEATER FORSUPPLYING DRIED HEATED AIR TO SAID TUB FOR DRYING THE CLOTES, SAID AIRCIRCULATING MEANS ALSO INCLUDING A BLOWER FOR WITHDRAWING AIR FROM SAIDTUB AND A DIVERTER VALVE FOR SELECTIVELY DIRECTING AIR FROM SAID BLOWERTO EXHAUST AND TO SAID CONDENSER, SAID CONDENSER INCLUDING AN MAIN AIRPASSAGE THERETHROUGH HAVING A PLU-